The primary objective of this Program is to advance an intravaginal ring formulation of a microbicide combination to safely reduce the sexual transmission of HIV. The overall Program includes 3 Projects and a Scientific Core and is comprised of several critical subcontracts that will enable the scientific team to achieve its goals. The interactions between the investigators, laboratories and clinical research sites are essential to the success of this Program. Consequently, a well-organized, well-defined administrative structure is necessary to optimize the success of this endeavor. The Administrative Core will oversee the day-to-day management of the Program and ensure communication and coordination of all study sites. The members of the Administrative Core will work closely with the investigators, pharmaceutical collaborators, NIH representatives and members of the designated Scientific Advisory Panel. The aims of the Core are to coordinate the fiscal and organizational aspects of the Program. The Core will be responsible for maintaining and reviewing budgets and will facilitate research related travel. In addition, administrative staff will be responsible for ensuring procurement and distribution of candidate microbicides as well as overseeing the shipment of clinical samples between the sites. The Administrative Core staff will arrange all study related confernce calls and annual meetings. The Core will also provide guidance to the Program Director, Project and Core Leaders for smooth, inter-institutional complex interactions, including assistance with subcontracts, IRB, Clinical Research Center and Ethics Committee submissions in New York and Rwanda, and identifying and resolving unanticipated problems.